Dummy bar with a separable dummy bar head



June 13, 1967 w. HESS ET AL 7 3,324,934

DUMMY BAR WITH A SEPARABLE DUMMY BAR HEAD Filed Aug. 31, 1964 W FIG] IN VIE/\"IYJRS WALTER HESS RIEDRICH WOLF m'mmams United States Patent 3,324,934 DUMMY BAR WITH A SEPARABLE DUMMY BAR HEAD Walter Hess, Dusseidorf, and Friedrich Wolf, Dusseldorf- Wersten, Germany, assignors to Schloemann Aktiengesellschaft, Dusseidorf, Germany Filed Aug. 31, 1964, Ser. No. 393,057 Claims priority, application Germany, Sept. 2, 1963, Sch 33,805 6 Claims. (l. 164-274) This invention relates to continuous casting and, more particularly, relates to a dummy bar with a separable dummy bar head for continuous casting apparatus.

In continuous casting, open ended molds are employed to form a strand from molten metal poured therein. In order to start the continuous casting process, a dummy bar having a dummy bar head is inserted into the apparatus to block the bottom of the mold. The molten metal poured into the mold is then prevented from escaping until initially formed into a strand. The dummy bar head is so formed that the end of the strand becomes secured thereto so that the dummy bar may be utilized to pull the strand from the mold until the strand reaches the driven extractor rolls in the casting apparatus.

At this position in the casting process, it is desirable to separate the dummy bar from the dummy bar head and to pull the dummy bar out of the way of the issuance of the strand. Various means of coupling the dummy bar head to the dummy bar such as by bolting or wedging the head to the dummy bar have been employed. However, separation of such heads from the dummy bar is difficult to accomplish in a continuous casting plant.

Various other devices such as slide locks and the like have been proposed but have been extremely difiicult to execute and have not been adapted for automatic separation of the head from the bar in the casting plant.

It is, therefore, an object of the present invention to provide an improved dummy bar and a head therefor coupled to said bar in such manner as to permit simple and expedient separation therebetween in automatic fashion during continuous casting runs. In accordance with this object, there is provided, in a preferred embodiment of this invention, an articulated dummy bar formed of chain links. The links are so formed as to spread the links preventing binding as the dummy bar is inserted along the guiding rollers. The head is coupled to the dummy bar by a jaw arrangement which supportably attaches the head to the dummy bar during insertion of the head into the mold and extraction of the strand therefrom. Upon reaching withdrawal rolls, however, automatic separation of the head from the dummy bar can be had by merely transversely deflecting the head from the direction of the dummy bar extraction.

Such dummy bars are particularly useful for the starting of strands using a curved strand guide as, for example, illustrated in US. Patent 2,947,075 to Schneckenbur er or U.S. Patent 2,920,359 to Easton. In such apparatus, dummy bars fabricated from resilient material have been employed. However, such dummy bars have limitations when casting strands of large cross section. Also, flexible dummy bars have been employed with certain difiiculties which arise due to binding and impacting upon the roller guides.

The dummy bar of the present invention is constructed from a plurality of chain links arranged in staggered rows and pivotally connected by bolts. The ends of each chain link is inclined with respect to the axis of the dummy bar so that the bearing pressure will tend to spread the chain links resulting in smooth withdrawal and the absence of impacts on the roller guides.

Having briefly described this invention, it will be described in greater detail along with other objects and advantages in the following portions of the specification, which may best be understood by reference to the accompanying figures, of which:

FIG. 1 is a side elevation of the dummy bar and dummy bar head constructed in accordance with the present invention;

FIG. 2 is a plan view of the dummy bar shown in FIG. 1; and I FIG. 3 is a schematic diagram illustrating the separation of the head from the dummy bar during extraction of the strand.

In FIGS. 1 and 2, there is shown a dummy bar and head. The dummy bar head 1 is coupled to the end of the dummy bar which is formed from a plurality of chain links 2, 3, 4 arranged in staggered array and interconnected pivotally by bolts 8. At the end of the dummy bar, the outer links 2 are coupled to the middle link 3 by oval shaped bolts 5. The dummy bar head is provided with jaws 6 which hook over the oval bolts 5. The outer links 2 are provided with projections 7 which engage the recesses formed at the head 1 in supporting engagement therewith. The ends of links 9 and 10 are preferably formed at an angle with respect to the transverse dimension of the bar 11. By this inclination of the mating faces, individual links of the dummy bar are spread outwardly, preventing binding and severe impacts upon the guide rolls.

The end faces of adjacent links bear on each other only in the bottom area 12, slots 13 being cut in the top area 14. By this arrangement, the dummy bar is articulated and can be bent upwardly by the distance limited by the slot 13 to follow the curvature of the strand guide during insertion of the dummy bar. The end strands are provided with slots 15 which extend over the entire mating face so as to permit deflection of the end links 2 and 3 in both the upward and downward direction.

By this construction, the dummy bar may be inserted along the strand guide curving upwardly to match the curvature of the strand guide until the head is positioned with respect to the continuous casting mold. Since the adjacent links bear on one another, the usual accordion eifect of an articulated chain link arrangement is avoided and the head may be controlled accurately. The head 1 is supportably engaged by the end of the dummy bar and can be positioned with respect to the mold in a controlled and supported arrangement. However, the head is not bolted or otherwise fixedly secured to the dummy bar which gives rise to problems in separating the head from the dummy bar. The ease of separation of the head from the dummy bar can best be seen by reference to FIG. 3 which shows three stages of strand extraction. As soon as the strand S is formed, forming a unit with the dummy bar head 1, the dummy bar is extracted. When the dummy bar K reaches the withdrawal and straightening device represented by the withdrawal rolls T, T, the reaction rollers R and the bending roller B, the end of the strand with the head attached moves upwardly with respect to the axis of the dummy bar. This is caused by the curvature of the strand, which curvature is introduced by the initial casting or by bending of the strand after casting. The dummy bar, however, will follow the designed course along the straightening roller bed. By virtue of this lifting of the head, the head will disconnect from the dummy bar with the jaws 6 disengaging from the oval bolts 5 and lifting ofi the projections 7. The dummy bar may then be extracted at a higher speed and as the strand reaches the bending roller B, the bending roller may be brought into straightening engagement with the strand. The construction of the dummy bar so that the head links thereof may deflect in either direction prevents the imposition of undesired afilicting forces to the dummy bar, which may damage the dummy bar.

Thus, with continuous casting apparatus casting a curved strand, the head can be automatically disconnected from the dummy bar during the process of guiding the strand and entering of the strand into the straightening devices. This automatic disconnecting alleviates many problems in continuous casting since it permits quick disconnection without interruption of the continuous casting process per se.

With rigid withdrawal bars which may, for example, be utilized in horizontal casting, the head may be connected to the dummy bar through the same jaw arrangement illustrated in the figures. For disconnecting of the dummy bar from the dummy bar head, the dummy bar may be deflected since the strand is withdrawn in a direct path and this process does not encounter deflection of the strand which is utilized in the embodiments shown for automatic separation of the head from the bar. In both arrangements, the projections 7 which are utilized for stabilization can be mounted on the dummy bar head engaged within corresponding slots in the dummy bar itself.

This invention may be variously modified and embodied within the scope of the subjoined claims.

What is claimed is:

1. A dummy bar and head assembly for a continuous casting machine comprising an articulated dummy bar, said dummy bar being formed of a plurality of links pivotally coupled together, the faces of adjacent links being inclined at an angle from the transverse dimension of said dummy bar, the end of said dummy bar being formed by projecting outer links and a middle link, bolts coupling said outer links to said middle link, a dummy bar head having projecting jaws, said jaws being adapted to engage said bolts for extraction of said strand and being disconnectable from said bolts by deflection of said head upwardly from the axis of said dummy bar.

2. A dummy bar and head assembly in accordance with claim 1 in which said plurality of links are arranged in rows extending along the axis of said dummy bar and in which adjacent rows of said links are staggered.

3. A dummy bar and head assembly in accordance with claim 1 in which said dummy bar head is provided with recesses and in which said outer chain links are provided with projections engaging said head supportably.

4. A dummy bar and head assembly in accordance with claim 3 in which the end links are defiectable over a limited distance in both directions from the axis of said dummy bar and in which the remaining links forming said dummy bar are deflectable in one direction only over a limited angle from the axis of said dummy bar.

5. A dummy bar and head assembly in accordance with claim 4 in which the adjacent end faces of each of said chain links supportably engage the end faces of the adjacent chain links.

6. A dummy bar and head assembly for a continuous casting machine comprising a dummy bar, a dummy bar head, a jaw and pin linkage coupling said dummy bar head to the end of said dummy bar, means for extracting said dummy bar and head after the strand has been formed in the mold and attached to the dummy bar head and means for inducing relative deflection between said dummy bar head and said dummy bar in a direction transverse to the direction of strand withdrawal to disconnect the dummy bar head from the dummy bar.

References Cited UNITED STATES PATENTS 953,700 4/1910 Maxfield 64-19 2,920,359 1/1960 Easton et a1 22-57.2 2,947,075 8/ 1960 Schneckenburger et a1. 2257.2 3,239,894 3/1966 Masters et a1 22-572 1. SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner. 

1. A DUMMY BAR AND HEAD ASSEMBLY FOR A CONTINUOUS CASTING MACHINE COMPRISING AN ARTICULATED DUMMY BAR, SAID DUMMY BAR BEING FORMED OF A PLURALITY OF LINKS PIVOTALLY COUPLED TOGETHER, THE FACES OF ADJACENT LINKS BEING INCLINED AT AN ANGLE FROM THE TRANSVERSE DIMENSION OF SAID DUMMY BAR, THE END OF SAID DUMMY BAR BEING FORMED BY PROJECTING OUTER LINKS AND A MIDDLE LINK, BOLTS COUPLING SAID OUTER LINKS TO SAID MIDDLE LINK, A DUMMY BAR HEAD HAVING PROJECTING JAWS, SAID JAWS BEING ADAPTED TO ENGAGE SAID BOLTS FOR EXTRACTION OF SAID STRAND AND BEING DISCONNECTABLE FROM SAID BOLTS BY DEFLECTION OF SAID HEAD UPWARDLY FROM THE AXIS OF SAID DUMMY BAR. 